Lights & Turn Signals for Electric Scooter

Here is how I made my scooter's lights using 3D printing and simple electronic components!

Light mounts are 3D printed, ensuring a perfect fit, while all the necessary electronic components are well integrated into both the scooter itself and the 3D printed parts.

There is a high probability that you may have a different electric scooter model. Therefore, this tutorial strives to be as universally applicable as possible, catering to all electric scooter owners. I am confident that you will find it valuable. Enjoy! :)

Warning: This project requires basic knowledge of electronics. I cannot be held responsible for any injuries or damages that may occur to you or your electric scooter during the process or afterwards! Additionally, please ensure that you comply with the laws of your country.

About tools:

1. 3D printer (of course!)
2. File, pliers and deburring tool
3. Drill and bit
4. Soldering iron and associated equipment
5. Srewdrivers
6. Multimeter
7. Heat-shrink sleeve, electric tape
8. Hot-glue gun and sticks
9. Personal Protective Equipment (PPE): protection gloves, goggles...

About materials and things to buy:

1. 5x M4 (16-20 mm lenght) CHC srews and nuts
2. Zip ties
3. Braided sleeve
4. 4x indicators/lights (I choose two red and two write), I bought mine on Amazon
5. ON/OFF switch (KCD1)
6. A turn signal switch, I found mine on Amazon
7. 2 meters of shielded 4x0,25 mm² wire
8. 0,25 mm² wire
9. 1,5 mm² wire
10. DC-DC converter module LM2596
11. TZT KY-019 (JQC-3FF-S-Z) relay module

The design:

I designed these mounts using SolidWorks CAD software.

I made efforts to ensure proper integration of the electronics, switches, and cable management. The main objectives were to introduce new features while keeping a nice look on my scooter! Additionally, to hold the light mounts in place on the handlebar, I incorporated mechanical keys to position and secure them by tightening the screws.

You can find STL files here: link to Cults3D

Later in the steps, you will notice that the holes for some electric wires (cable from right front mount to scooter's electronics and cable from right front mount to left front mount) are missing. In order to keep your control panel (right front mount) fully waterproof, just drill two holes in the 3D printed part with the correct diameter for your wires.

About mounts compatibility:

I've designed the mounts for my Ninebot Segway D-Series electric scooters (mine is D38E). They should be compatible for other scooter and Ninebot's series such as F-Series and more!

Here are some useful informations to check compatibility with your scooter:

• Scooter handlebar outer diameter: Ø22 mm
• Width of the right front mount (with switches): 50 mm
• Width of the left front mount: 37 mm
• Gap width of rear mounts: 8 mm
• Dimensions of the mechanical keys: 9.55 mm (height) * 7.7 mm (width) * 44 mm (length) & 9.55 mm (height) * 7.7 mm (width) * 31 mm (length)

Here we go for a printing work!

I printed all the parts using PLA materials with a layer height of 0.2 mm.

Due to the shape of some parts, you will need to use supports during printing and remove them afterward. You can use files and pliers to clean up your parts.

Let's dive into the exciting part!

My objectif was to determine the correct method of connecting the lights to my electric scooter while considering the following specifications:

• Lights require a 12V power supply with low current
• Electric scooters operate at higher voltages (for my D38E, it's around 36-40V)
• I don't want to consume the battery when my scooter is turned off, and I want to avoid using an external power source
• Electronics must be integrated inside the scooter for aesthetic and waterproof reasons

Before getting started, unplug your scooter and strive for meticulousness in the following steps. Here are some important rules to keep in mind:

• Be careful not to make electrical contact with your tools
• Make sure to keep your electrical box clean and dry at all times
• Pay extra attention to the battery connections and capacitors

First, find the way to open the electronic box of your scooter. Personally, I had to unscrew four screws in order to access to my speed controller. Sometimes, screws can be hidden under the grip of your scooter deck (in my case, there were two screws hidden under the D38E grip's).

Take your time to identify the different components of your scooter, such as the speed controller, battery, motor and LCD display connections, battery input on your speed controller, etc.

On my scooter circuit boards, there were different plugs:

• LCD display (purple arrow)
• Rear light (red arrow)
• Battery power input (orange arrow)
• Battery monitor (green arrow)
• Motor power output (blue arrow/circle)

Clear blue arrow is the charging socket.

You can try unplugging the various connectors to aid in the identification of your components. Observe the effects when you turn on your scooter, if possible, depending on what you have unplugged!

After identifying the different components. it's a good idea to use a multimeter to investigate and measure voltages at various points on your scooter's electronic. This will give you useful ideas to develop your electrical diagram.

As an example, here is my electrical diagram and the reasons behind the choices I made:

• I have a voltage step-down component, which means that I need to connect my lights to a voltage that is higher or equal to the voltage needed for my lights (12 V). To achieve this, I chose to connect the step-down component to the "Battery power input" (indicated by the orange arrow from the previous step), as it provides the necessary voltage.
• To prevent battery consumption when my scooter is turned off, I incorporated a relay module. This module cuts the power supply to my lights when it is not stimulated by a 5V voltage.
• During my investigations using a multimeter, I discovered that the "rear light" plug (indicated by the red arrow from step 3) has a voltage of 5V. Additionally, this plug is activated and deactivated when I turn my scooter on and off. Therefore, I decided to use this plug to control the relay module as well.
• The lights have three wires: the black wire is negative, the yellow wires are positive for indicators, and the white or red wire (depending on whether it is for the front or rear lights) are positive for the lights. In my setup, I chose to permanently connect the red wires to the positive terminal. The white wires have a switch for control.

Notes: The lights I chose have their own gradual lighting effect, which, in my opinion, is pretty cool. When the lights are on and receive a positive signal on the indicator wire, they will automatically switch from a steady light to a turn indicator.

Moment of truth: It's time to test your electrical diagram and see if everything has been done correctly!

Follow your electrical diagram step by step and connect the different components accordingly. You can use a breadboard if you have it.

Everything works? Well done! Let's continue with your final wiring.

Here are some wiring tips and rules to keep in mind:

• Ensure that you solder your connections properly and use heat shrink sleeves or electrical tape to provide insulation and protection.
• Use a larger wire section for higher current applications, especially for connections between the battery and the step-down module.
• Steps 5 to 8 need to be done simultaneously. Make sure to review them before proceeding further.

It's an excellent idea to double-check your work by testing your incomplete electrical system for each important wiring step:

• When you wire the relay module, you should be able to hear it switch. You can also measure the voltage drops caused by the relay (assuming you have also wired the "Battery power input").
• When wiring the DC voltage step-down, a red light should illuminate. This is also the moment to adjust the voltage to 12V by turning the potentiometer on the step-down module.
• Before finalizing the mounts, test the lights and indicator buttons to ensure they are functioning correctly.

Regarding disassembling:

To proceed with my cable management, there are two main spots on my scooter that I had to disassemble: the electronic box and the scooter bar.

Electronic box: This is where I housed all the electronics for my lights. The cables for the front and rear lights are routed out from this spot.

Scooter bar: In order to facilitate cable routing, it can be useful to disassemble the scooter handlebar.

Regarding waterproofing:

My scooter has an IPX5 rating, which means it can be used on a rainy day. However, by undertaking this project, I will be compromising its waterproof capability. Therefore, in order to maintain some level of water resistance, it is important to take the following precautions:

• Pay attention to every seal and cover. Make sure you are able to properly re-mount them and consider what needs to be resealed.
• After routing your cables through the scooter, it's important to reseal any gaps or openings to maintain water resistance. In my case, I created gaps in the black silicone I found on my scooter and used a hot glue gun to reseal them.

Front lights installation, follow these steps:

1. Unscrew the nut of the light and set it aside. Insert the light's wire into the hole of the 3D printed part, then place the nut back on.
2. Screw the light onto the mount and tighten it lightly.
3. Insert the light cable into the cable path of the 3D printed mount. You should have something similar to the first picture.
4. Repeat the same steps for both 3D printed mounts and lights.
5. Due to the short distance of the cables for the scooter accelerator and brake, I had to remove the LCD screen to access the screws for disassembling the T-bar. This step is necessary to slide the light mounts onto the handlebar. The screws were hidden under black silicone.
6. Unscrew brake and accelerator from the handlebar.
7. Slide them out from the handlebar and place the 3D printed mounts on it.
8. Put back the accelerator and the brake.
9. Perform cable management between the left and right front mounts. I used a braided sleeve and passed it through the handlebar (refer to the picture).
10. Place the mechanical keys to lock the 3D printed mounts in place.
11. Ensure everything is correctly positioned on the handlebar and tighten all screws.
12. Using a drill or soldering iron, make two small holes on the 3D printed mount (the one with buttons) for your cables (electronic box and left front mount cables). Make the holes as small as possible to ensure waterproofing of your connections.
13. Following your electrical diagram, make your electrical connections. Test them to ensure proper functionality.
14. Use hot glue to seal the holes and gaps for waterproofing.
15. Fit your buttons into the 3D printed mounts.

Rear lights installation, follow these steps:

1. Organize the cables between the electronic box and the rear left and right lights, ensuring proper cable management. Use a hot glue gun and zip ties to secure the wires in place.
2. After soldering the connections between the left and right lights, use braided sleeves, heat-shrink sleeves, and electrical tape to ensure waterproofing and reliable connections. Test the connections to verify their functionality.
3. Place the 3D printed mounts on your scooter and install the lights onto them, referring to the provided pictures.
4. Secure the lights and mounts in place using zip ties.

Well done, you've made it!

This project can help you expand your knowledge in the areas of 3D printing and electronics.

I hope this tutorial has been helpful and inspiring. Don't hesitate to share your own light systems with us.

If you have any questions, feel free to ask, and I will try to answer them.

Happy making!